Segment Reporting Assets and Liabilities by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total Assets	$ 15,315,930	$ 14,085,886
Liabilities	13,780,318	12,865,000
Total Equity	1,535,612	1,220,886	$ 1,323,556	$ 921,572
Investment Portfolio Segment
Segment Reporting Information [Line Items]
Total Assets	5,978,988	5,635,657
Liabilities	4,555,212	4,499,669
Total Equity	1,423,776	1,135,988
Longbridge Segment
Segment Reporting Information [Line Items]
Total Assets	9,092,840	8,227,509
Liabilities	8,872,153	8,092,313
Total Equity	220,687	135,196
Corporate and Other
Segment Reporting Information [Line Items]
Total Assets	244,102	222,720
Liabilities	352,953	273,018
Total Equity	$ (108,851)	$ (50,298)